Bottom up approach

• the bottom up approach

  • UK approach
  • Developed by Canter
  • uses investigative psychology and geographical profiling
• 2 parts of the bottom up approach

  • investigative psychology
  • geographical profiling
• investigative psychology

  Analysing behaviour and evidence from a crime scene to identify patterns
• 3 assumptions made in investigative psychology

  • interpersonal coherence - there is a consistency between how offenders interact with their victims and others in their life
  • Significance of time and place - location and time of the crime communicates something about the offender’s place of residence or workplace
  • Criminal characteristics / forensic awareness - people who have been questioned before will know procedures and cover their tracks
• geographical profiling

  using information about the location of linked crime scenes to make inferences about about the ‘operational base’ of the offender - crime mapping
• Canter & Larkin - circle theory

  assumes that a pattern of offending forms a circle around an offender’s home or base
• 2 ways of offending according to the circle theory

  • marauders - operate in close proximity to their home or base
  • commuters - travel to a distance from their home or base
• what insight into the offence can spatial decision making offer in geographical profiling?

  • whether it was planned or opportunistic
  • the offender’s mental maps
  • mode of transport
  • approximate age
• the John Duffy case

  • known as the ‘railway rapist’
  • committed 3 murders and 24 sexual attacks
  • aspects of modus operandi suggested links between the attacks
  • all attacks were near railway stations
  • Canter helped to draw up a profile and all predictions were correct
• strengths of the bottom up approach

  • scientific and successful - based on statistical analysis eg in the John Duffy case
  • supporting evidence - Canter & Heritage
• Canter & Heritage

  analysed 66 sexual offences and suggested 5 variables central to the cases

  • vaginal intercourse
  • no reaction to the victim
  • impersonal language
  • surprise attack
  • victim’s clothing disturbed

  was able to identify patterns, helping to catch sexual offenders
• weaknesses of the bottom up approach

  usefulness - Copson found that only 3% of police officers said that investigative profiling actually helped them to identify the perpetrator

  Rachel Nickel case
• the case of Rachel Nickel

  • stabbed 47 times and sexually assaulted
  • her 2 year old son was the only witness
  • Colin Stagg was targeted as he fit the profile but there was no other evidence
  • he was actually innocent
  • Robert Napper was later convicted of the murder